#include <stdio.h>

int main () {
  int h = 0;
  int w = 0;
  int k = 0;
  int x = 0;
  int y = 0;
  long long v[50][50] = {};
  
  int res = 0;
  
  long long ans = 0LL;
  long long mod_num = 998244353LL;
  
  res = scanf("%d", &h);
  res = scanf("%d", &w);
  res = scanf("%d", &k);
  for (int i = 0; i < k; i++) {
    res = scanf("%d", &x);
    res = scanf("%d", &y);
    res = scanf("%lld", v[x-1]+(y-1));
  }
  
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      for (int x = 0; x < h; x++) {
        for (int y = 0; y < w; y++) {
          if (x+y >= i+j && x-y >= i-j) {
            ans += v[x][y];
          }
        }
      }
    }
  }
  
  printf("%lld\n", ans%mod_num);
  return 0;
}